I've been asked to install a commercial range hood in a fancy residential kitchen. The hood is in good used condition with luminaires identified for the application. It is wired so that the junction box is on the outside of the hood with EMT conduit penetrating the side and routed through the hood's ceiling to each fixture. Hi-temp conductors throughout etc. Referencing NEC 99 & 02 (my 05 code is in my shop, regardless, here in NYS we are still working under the 99 code) 410.4(C)(4) ..."wiring methods and materials supplying the luminare(s) fixtures shall not be exposed within the cooking hood" what would be your definiation to "exposed"? Also, does this code apply to a commercial hood installed in a single-family residential kitchen?

I'd rather not route the conduit on the exterior of the hood as it will be plainly visible.

I don't think I've ever seen a hood that did not have EMT run inside it. There are a few reasons, best as I can see: - Hood penetrations are kept to a minimum, for cleaning purposes. Where the pipe does go through the hood, special fittings - NOT available to electricians - are used that seal all around the conduit. This is, as I understand it, a requirement of the hood fire code, as well as a means to keep cleaning materials within the hood; and,

- Many hoods - again, for fire reasons - are made with a double wall. Making penetrations, and sealing them, is problematic at best.

The presence of the pipe within the hood does not seem to be any obstacle to the cleaning operations. Nor does the pipe seem to be damaged in the least by the chemicals.

I'd be interested in learning the history of that code wording.

Now, as far as I know, that same section of the NEC is worded such that it only applies to commercial installs. Not that it's a bad idea ... I once encountered a custom-made hood in a house that was not in compliance, and I quite merrily cited this part of the code to make the contractor get rid of the exposed romex and keyless fixtures! (I even posted pics at ECN).

Hood and fan was existing to be re-installed. The exhaust is ducted thru the wall and it's wiring is not "exposed". Both switches are typically mounted outside the unit and the switched legs are concealed within wall, etc. The lighting leg exits wall outside of the hood and is discretely routed to where it enters a junction box outside of the hood. No make up air, no fire supression system, fire-rated back wall, shunt-trips, etc. It's residental. Right?

The inspector saw the hood sitting outside when he did the service inspection and quoted this code to me. I think I'll just let him check out the finished product for himself and give the HO the bad news. Maybe they'll even make us sprinkler and supervise the place when they find out what a big party they throw every christmas.

In the handbook notes in my 2002 NEC it says that this is taken from NFPA 96 which includes all hoods except those installed in single family dwellings.Notes say that "wiring systems, including RMC, are not permitted to be run exposed within the cooking hood."I'd look up NFPA 96, discuss the notes in 99 NEC for this section if they are similar, and say that this is not a commercial location where the hood is installed. I'd also use EMT compression fittings that are water-tight. Some are not...